If you pull the money out you will have to pay a 10% penalty tax plus you will have to pay income tax on the withdrawal. Only do this if you absolutely need the money. I would roll it over into an IRA, then possibly convert to a Roth IRA either this year or next. You will need to speak with your company to get the process started on any of these options. Call me with questions.
Best thing you can do for your 401k is either roll it over to an IRA or roll it into your new employers 401k. You will be hit with a large penalty if you withdraw your 401k money if you are under a certain age (Mid 50's) depending on the situation!